A package structure is provided. The package structure includes a leadframe, a GaN power device, and an electrostatic discharge protection component. The leadframe includes a gate pad, a source pad, and a drain pad, which are disposed on the leadframe. The GaN power device has a gate end. The GaN power device is disposed on the source pad of the leadframe. The electrostatic discharge protection component includes a first pad. The first pad is disposed on the electrostatic discharge protection component. The electrostatic discharge protection component is disposed on the source pad of the leadframe. The gate end of the GaN power device is electrically connected to the first pad of the electrostatic discharge protection component. The first pad of the electrostatic discharge protection component is electrically connected to the gate pad of the leadframe.